Sealing/caulking toilet on a tile floor?

[trader-of-some-jacks]

In cleaning a bathroom floor recently, I wound up essentially removing much of the caulk around the base of the toilet.

As the toilet is right near the shower, and there is a good deal of water splash outside the shower stall, it's necessary to have some kind of seal around the toilet base, to protect from leakage.

But when I put down new caulk, it just didn't adhere. This is caulk I've used to seal tubs, shower stalls, etc. What am I doing wrong? It's a "regular" toilet, and the floor is one of those late-70s era floors with little slippery tiles and grout in between.

[Sylvan Butler]

Most likely some cleaning residue on the tile.

sdb

[Robert Allison]

I would be willing to bet that the old caulk was silicone. If that was the case, then you will have to use silicone to replace it as the silicone leaves a residue that nothing else will adhere to. That is one of the many reasons that I never use silicone except on glass.